56 Inlu'ritcmcc (did Evolution iit Orthoptt r<t IV 



systems ure equally well known, having been studied in mice, guinea- 

 pigs, Drusophila, and corn. Nabours ('14) published an account of his 

 work with Paratettix in which he described what has since been 

 recognized (Dexter, '14) as a system of multiple allelomorphic charac- 

 ters, — the most extensive system yet reported. Nabours showed the 

 existence of eight colour patterns, each allelomorphic to any of the 

 others. Since that time, not only has the behaviour of the eight 

 characters been fully confirmed, but the system has been extended 

 t<i include in all, at least fourteen patterns and probably several more 

 (Nabours, 17). 



Material and Method. 



The material used in this study was collected near Houston, Texas, 

 by Dr Robert K. Nabours and turned over to the writer in October, 1914. 

 I am under deep obligation to him for aid by way of suggestion, 

 encouragement, and criticism. 



All the specimens used in the laboratory appear to confoi-m most 

 closely with Hancock's description of Tettigidea parvipeiinis pemiata 

 Morse. 



Occurrence and distrihution. The Tettigidea are widely distributed, 

 frequenting the damp surfaces of more or less deeply shaded areas, where 

 mosses, lichens, algae, and decaying vegetation, upon which they feed, 

 are to be found. 



Life History. That part of the life cycle from the egg to the adult 

 may be completed in five or six weeks, although mating and deposition 

 of eggs may not occur, at least in the laboratory, for several weeks after 

 the last moult. In one instance, e.g. series (9) of Table I, the first young 

 of the parental generation hatched February 9, 1915. Two females 

 became adult March 9, one of which was mated on March 11, to her 

 father, producing the second generation of young April 22, a little over 

 eleven weeks fi-om the hatching of the first generation to the hatching 

 of the second. 



Technique. In the laboratory the grasshoppers are bred in cylindrical 

 screen <jr glass jars set in pots of moist sandy loam, the surfaces of 

 which are covered with a thin layer of peat. The bottom of a small 

 three-inch pot protrudes about one-half inch above the surface of the 

 soil in the centre of each jar, aftbnling a clean jiilaee ujjon which to 



